Generally, a rear-seat armrest is rotatably mounted between both side seatbacks. In an ordinary state, as shown in FIG. 1, a rear-seat armrest 2 is folded inwardly toward seatbacks 1 and is thus vertically inserted between the seatbacks 1, and when necessary, the rear-seat armrest 2 is unfolded forward from the seatbacks 1.
When a passenger on a rear seat unfolds the armrest 2 forward when necessary, the rear-seat armrest 2 is positioned horizontally with respect to a rear-seat cushion 3, and one or more passengers on a vehicle may rest all their arms on the armrest 2 to maintain comfortable their postures, which allows the passengers to experience a gentle ride.
FIG. 2 is a perspective view showing a conventional rear-seat armrest rotation structure. An armrest rotation apparatus 4 includes a hinge bracket 5 which is hinge-coupled to both-side surfaces of a lower end portion of an armrest 2 via a central shaft 6 to rotatably support the lower end portion of the armrest 2.
The hinge bracket 5 is a “”-shape plate, and the central shaft 6 is inserted through a hinge hole formed in both-side surfaces of the plate, such that the hinge bracket 5 is hinge-coupled to the both-side surfaces of the lower end portion of the armrest 2.
On the both-side surfaces of the hinge bracket 5 are formed guide holes 7 having a predetermined radius from the central shaft 6 in a rotation direction, and guide pins 8 are inserted through the guide holes 7 to be coupled to the both-side surfaces of the lower end portion of the armrest 2, such that as the guide pins 8 rotate up and down along the guide holes 7 to stably guide rotation of the armrest 2.
With such a rotation structure, an upper end portion of the armrest 2 rotates up and down with respect to the central shaft 6 of the hinge bracket 5, and when necessary, the armrest 2 is unfolded horizontally to rest an arm thereon.
However, the conventional rear-seat armrest 2 has no separate locking apparatus, such that in a forward collision with another car or object in front of the car, the armrest 2 becomes unfolded due to inertia and a passenger may bump into the unfolded armrest 2. This may threaten the passenger's safety.
In particular, when a child lies down on the rear seat, when the forward collision occurs, the armrest 2 rotates and hits a face of the child, causing a serious safety accident.